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Performance, meat quality, meat mineral contents and caecal microbial population responses to humic substances administered in drinking water in broilers a
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E. Ozturk , I. Coskun , N. Ocak , G. Erener , M. Dervisoglu & S. Turhan
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Department of Animal Science, Faculty of Agriculture, Ondokuz Mayis University, Kurupelit, 55139 Samsun b
Department of Animal Science, Faculty of Agriculture, Ahi Evran University, Asikpasa, 40000 Kirsehir c
Department of Food Engineering, Faculty of Engineering, Ondokuz Mayis University, Kurupelit, 55139 Samsun, Turkey Accepted author version posted online: 03 Sep 2014.
To cite this article: E. Ozturk, I. Coskun, N. Ocak, G. Erener, M. Dervisoglu & S. Turhan (2014): Performance, meat quality, meat mineral contents and caecal microbial population responses to humic substances administered in drinking water in broilers, British Poultry Science, DOI: 10.1080/00071668.2014.960807 To link to this article: http://dx.doi.org/10.1080/00071668.2014.960807
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Publisher: Taylor & Francis & British Poultry Science Ltd Journal: British Poultry Science DOI: 10.1080/00071668.2014.960807
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CBPS-2014-099 Ed. Kjaer, July 2014; MacLeod, August 2014
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responses to humic substances administered in drinking water in broilers
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E. OZTURK, I. COSKUN1, N. OCAK, G. ERENER, M. DERVISOGLU2 AND S. TURHAN2
Department of Animal Science, Faculty of Agriculture, Ondokuz Mayis University, Kurupelit, 55139 Samsun, 1Department of Animal Science, Faculty of Agriculture, Ahi Evran University, Asikpasa, 40000 Kirsehir and 2Department of Food Engineering, Faculty of Engineering,
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Ondokuz Mayis University, Kurupelit, 55139 Samsun, Turkey
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Running title: Humıc substances as growth promoters
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Performance, meat quality, meat mineral contents and caecal microbial population
Correspondence to: Ergin Ozturk, Ondokuz Mayis Universitesi, Ziraat Fakultesi, Zootekni Bolumu Kurupelit, 55139 Samsun, Turkey. E-mail: [email protected] Tel: +90–362–31231919 x (1144). Fax: +90–362- 4576034.
Accepted for publication 10 thJune 2014 1
Abstract 1. This study was conducted to examine the effect of different levels of humic substances (HS) administered in drinking water on caecal microflora and mineral composition and colour characteristics of breast and thigh meats as well as the growth performance, carcass and gastrointestinal tract (GIT) traits of broiler chicks. 2. A total of 480 3-d-old broilers chickens were randomly allocated to 4 treatments with 4
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cages per treatment and 30 birds (15 males and 15 females) chicks per cage. All birds were
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additions whereas birds in the other treatment groups received a drinking water with 7.5
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(HS7.5), 15.0 (HS15.0) and 22.5 (HS22.5) g/kg HS. Mush feed were provided on an ad libitum basis. Body weight and feed intake of broilers were determined at d 0, 21, and 42, and
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feed conversion ratio was calculated. On d 42, 4 broilers (2 males and 2 females) from each cage were slaughtered and the breast and thigh meats were collected for mineral composition and quality measurements.
3. Performance, carcass and GIT traits and caecal microbial population of broiler chicks at d
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42 were not affected by the dietary treatments. The lightness (L*) of breast and thigh meat decreased in broilers supplemented with 15 g/kg and 22.5 g/kg HS in drinking water. While the redness (a*) of breast meat increased, yellowness of thigh meat decreased in broilers
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supplemented with 15 g/kg and 22.5 g/kg HS in drinking water (P < 0.05). 4. In conclusion, the 15 g/kg and 22.5 g/kg HS administration in drinking water can be applied for broiler chicks to maintain growth performance and improve meat quality without
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fed on commercial basal diet. The control birds (HS0) received drinking water with no
changing caecal microflora. INTRODUCTION
The optimum growth and economical feed conversion as well as prevention and control of diseases are dependent on the feed additives (Ozturk et al., 2012). There is a large variety of feed additives including organic acids such as acetic, propionic, butyric, formic, citric, fumaric, lactic, malic acid and humic acids or commercial acid blends (Islam et al., 2005; 2
2008; Esenbuga et al., 2008; Ocak et al., 2009; Ozturk et al., 2010, 2012), that can be used to replace antibiotic growth promoters. Humic substances (HS) are major components of the natural organic matter in soil and water as well as in geological organic deposits such as lake sediments, peats, brown coals and shales (Islam et al., 2005). The HS, humic, fulmic and ulvic acids are not antibiotics but, if used correctly along with nutritional, managerial and bio-
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security measures, they can be a powerful tool in maintaining the health of the gastrointestinal
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al., 2003; Windisch et al., 2008). Most of the data on humic, fulmic, ulvic acids and humin
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refer to average properties and structure of a large ensemble of components of diverse structure and molecular weight (Islam et al., 2005; Ozturk et al., 2010, 2012). The properties
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of HS are well documented (Islam et al., 2005; Peña-Méndez et al., 2005; Ji et al., 2006). Studies investigating the effects of the HS and/or humic acids administration in the diet or drinking water on live weight, feed consumption and characteristics of carcass and GIT in broiler chickens (Rath et al., 2006; Ozturk et al., 2010, 2012; Šamudovská and
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Demeterová, 2010) indicated that HS improved protein digestion and trace element utilisation (Huang et al., 1994; Yang et al.,1996,), and it has a positive influence on growth rate (Shermer et al., 1998; Eren et al., 2000; Kocabagli et al., 2002; Ceylan et al., 2003). We
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found that the HS supplementation at levels of 300 g/kg and 450 g/kg in drinking water appears to have a measurable impact on live performance by improving feed efficiency and lightness of breast and thigh meat in broilers, respectively (Ozturk et al., 2010). Also we
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tract (GIT) of poultry, thus improving their performances (Kocabagli et al., 2002; Ceylan et
found that feeding with a diet containing HS caused a measurable variation in the meat quality and blood cholesterol as well as the performance, carcass, and GIT traits of broilers. The antimicrobial effects of humic substances, including humic acid, have been demonstrated, but the reports on their influence on growth performance of poultry are variable, therefore, it needs more investigation (Ozturk et al., 2010, 2012). On the other hand, little is known on whether humic acid shows an antimicrobial effect against opportunistic pathogens existing in 3
gastrointestinal tract (Islam et al., 2008). Thus, the aim of this study was to evaluate the effects of different doses of HS supplementation provided through drinking water on growth performance, characteristics of carcass and gut, gut microflora and colour characteristics of breast and thigh meat in broilers. MATERIALS AND METHODS
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For the trial, 480 3-d-old broiler chicks (ROSS 308), were allocated into 4 groups (HS0,
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replicates of 30 chicks (15 females and 15 males). All birds were fed ad libitum the same
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antibiotic-free commercial diet for the starter (from d 1 to d 21), grower (from d 22 to d 35) and finisher (from d 36 to d 42) periods (Table 1). All animals in experimental treatments
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were housed in floor pens with wood shavings and fed on the same basic diets. The control birds (HS0) received drinking water with no additions. Birds in the other treatment groups received a drinking water with 7.5 (HS7.5), 15.0 (HS15.0) and 22.5 (HS22.5) g/kg HS per kg of body weight. The liquid HS, measured for each of treatments was added into a sufficient
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amount of drinking water based on estimated water consumption recommended by the producer company. Therefore, drinking water was prepared daily for each of treatments and also to ensure consumption of HS treated water, the treated water up to the half of daily water
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requirement were given by plastic poultry drinker. After all of the HS treated water was consumed, birds were watered ad libitum by automatic drinkers. Thus, daily water intake was not measured. The HS used in present study was reported to include 4.9% dry matter, 61.2%
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HS7.5, HS15 and HS22.5) of 120 mixed-sex birds. Each treatment was divided into 4
humic acid, 5.1% fulvic acid, 7.53% crude protein, 0.48% crude fibre, 2.35% ether extract, 2.49 % Ca 0.24%Mg, 0.15% K, 1.09% N, 1.49% S, 0.07% P, 0.28% NO3-, 1.89% Fe, 0.05%
Zn, 0.02% Cu, 0.01% Ni, 0.02% Cr, respectively (Ozturk et al., 2012).
Table 1 near here
During the trial, continuous lighting was provided throughout the experiment. Ambient temperature was gradually decreased from 33 °C on d 7 to 21 °C on d 21 and was kept constant. All the cages were checked for mortality twice a d and mortality was recorded as it 4
occurred and was used to adjust the total number of birds to determine the total feed intake per bird and FCR. Live weight and feed intake were measured at 1, 21, 35 and 42 d of age. The birds were weighed and fed as mixed sex in each group. Therefore the chick weight, the daily weight gain and the feed efficiency was not determined per sex. At 42 d of age, birds were starved for 6 h before slaughtering and 4 birds (2 females and 2 males) per replicate or
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16 birds per treatment were slaughtered (Ozturk et al., 2010, 2012). Plucked and eviscerated
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ready-to cook carcasses that were refrigerated for 6 h at 4 °C. Yields from chilled carcasses,
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breast and thighs were evaluated. Breast (Pectoralis major) and thigh (Iliotibialis) meat samples were vacuum-packaged and kept frozen (-20 °C) until chemical analyses were
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performed.
The CIE colour values of meats (lightness (L*), redness (a*), and yellowness (b*)) were measured at 8 h post-mortem using a Minolta CR 300 Chroma Meter (Minolta Camera Co., Osaka, Japan). Four replicate measures were performed on breast and thigh meats,
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respectively, representing the whole surface of the muscles and mean colour values were calculated for each sample. The colorimeter was calibrated throughout the study using a white and pink ceramic tile. A white tile (L* = 92.30, a* = 0.32, and b* = 0.33) was used as
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standard. Lightness may range from 100 (white) to 0 (black). While positive a* and b* values are a measure of redness and yellowness, respectively, negative a* and b* values indicate greenness and blueness. Mineral composition of breast and thigh meat was determined with
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carcasses were weighed after removal of the head, neck, feet and abdominal fat to obtain
atomic absorption spectrophotometer, except P that was analysed with an atomic absorption spectrophotometer (Horuz and Korkmaz, 2006). Pre-weighed ileum samples (1 g) for microbiological analyses were transferred into dilution bottles. Anaerobic diluents were added to achieve a 1 to 10 (w/v) dilution. The samples were mixed with a vortex until completely suspended and dispensed using standard methods into a 1 to 10 (v/v) dilution series of tubes containing anaerobic peptone buffer. 5
Appropriate dilutions were inoculated onto the plates. The following media and incubation conditions were used to enumerate microbial counts of samples: Rogosa agar for lactobacilli at 30oC for 5 d, Plate Count agar for aerobic mesophilic bacteria at 30oC for 48 h, Violet-Red Bile agar for coliform bacteria at 35oC for 24 h, M17 agar for lactococci at 30oC for 72 h and Chromocult TBX agar for Escherichia coli (E. coli) at 44oC for 24 h.
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For performance data, pen means served as the experimental unit for statistical
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composition, blood parameters and caecal microbial population, slaughtered individual birds
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were considered as the experimental unit. All percentage data were transformed by taking arcsine square roots prior to analysis. In order to evaluate statistically the measured data, one-
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way analysis of variance (ANOVA) was performed in a completely randomised design: ˆYij = μ + αi + eij (ˆYij: observation values (body weight gain, feed consumption, feed to gain, carcass traits, colour measurements, blood parameters, etc.), μ: the overall mean, αi: the effect of the ith treatment (i: 1, . . ., 4; HS0, HS7.5, HS15.0 and HS22.5) and eij = residual error).
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Tukey's test was used to determine the effect of treatments and differences which were considered to be significant at P < 0.05. RESULTS
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No significant differences in mortality among the treatment groups (0.83%, 1.67%, 0.83% and 0.83% for the HS0, HS7.5, HS15 and HS22.5, respectively) were observed. Daily weight gain, daily feed intake and feed efficiency of broilers receiving the HS supplemented drinking
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analysis. For data of relative weights and length of gut, meat quality traits, chemical
water are presented in Table 2. The daily weight gain, daily feed intake and feed efficiency
were not affected by the treatments (P > 0.05). Therefore, HS administered in drinking water did not have any harmful effects on performance, and had no growth-promoting effect compared to control on broilers.
Table 2 near here
Means for carcass weight, dressing percentage, the relative weight and length of gut and the relative weight of edible inner organs (such as gizzard, heart, liver) and abdominal fat 6
pad at 42 d of age are shown in Table 3. There were no differences among the experimental groups compared to the control group in terms of the carcass weight, dressing percentage, the relative weight and length of gut and the relative weight of edible inner organs and abdominal fat pad (P > 0.05). The L* and a* values of breast and L* and b* values of thigh meat were affected by
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HS supplementation (Table 4), the L* values of breast meat were higher at 0HS than that of
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lower than those from other treatment birds (P < 0.05). The L* values of thigh meat was
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higher in control and 7.2HS birds than those in other treatments (P < 0.05). The thigh meat from all of the HS treatment groups had a higher a* value compared to the HS0 (P < 0.05).
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Mineral composition of breast and thigh meats of broilers receiving the HS supplemented drinking water is presented in Table 5. Percentages of Ca, Mg, K, Na, P, Fe and Cu of breast meat were not affected by the dietary treatments, but content of Zn increased by HS7.5 in respect to 0HS. Percentages of Ca, Mg, K, Na, Cu and Zn of thigh meat were not
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affected by the dietary treatments, but percentage of P was higher in HS7.5 compared to HS15 whereas Fe level was higher in HS22.5 compared to HS7.5.
Tables 4 and 5 near here
Bacterial counts (log10 cfu/g) from the caecal of broilers receiving HS-supplemented
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drinking water are presented in Table 6. Aerobic mesophiles, lactococci, lactobacilli, coliforms and E. coli counts in caecum were not affected by HS in drinking water (Table 6).
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15HS and 22.5HS groups (P < 0.05). The b* values of breast meat from 22.5HS birds were
DISCUSSION
Table 6 near here
The results of the present study indicated that the 15 g/kg and 22.5 g/kg HS administration in drinking water can be applied for broiler chicks to maintain growth performance, without changing caecal microflora, and to improve meat quality. In the present study, mortality was low and within the accepted limit for all groups, and the deaths was not associated with any specific treatment. Our result could be considered as similar to our previously observations (Ozturk et al., 2010, 2012). Likewise, Rath et al. (2006) and Kocabagli et al. (2002) found no 7
differences in mortality in their study. It can be said that the potential interactions of HS with commonly occurring pathogens or environmental stress can hardly be evaluated under the controlled conditions. Therefore, it is considered that the cause of death of chickens in control and HS groups was the sudden death syndrome, conforming to the results of studies by Yoruk et al. (2004), Karaoglu et al. (2004) and Islam et al. (2008). The fact that HS treated water did
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not induce deterioration in feed intake and weight gain in our present and previous study
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Indeed, we observed that, in the both experiments, birds consumed voluntary all of the HS
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treated water.
External appearance (colour) of meat and consistency of colour as well as water-
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holding capacity and texture are important meat quality characteristics that can affect consumer preferences (Fletcher, 2002; Qiao et al., 2002). Moreover, there is a relationship among some meat quality parameters such as colour attributes (CIE L*, a* and b*), pH and water-holding capacity (Fletcher, 2002). Colour of meat is not only a quality characteristic,
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but is also an indicator of animal health, related directly to stress and energy metabolism (Nijdam et al., 2005; Kop and Ocak, 2009). Therefore, one of the primary aims of the present study was to investigate the changes in colour characteristics and chemical compositions of
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both breast and thigh meats. Yoruk et al. (2004) have demonstrated that darkening in thigh muscles and an increase in their redness might indicate an increase in haem pigments because the red colour in meat is due mainly to a protein pigment called myoglobin and, to a lesser
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(Ozturk et al., 2010) indicate that HS given in drinking water did not affect water intake.
extent, haemoglobin. Ozturk et al. (2010) have reported that inclusion of 0.5 g/kg HS via water enhanced a* values of broiler breast and thigh meat and Ozturk et al. (2012) have hypothesised that the increase of a* values of breast and thigh meat might result from increased iron content of breast and thigh meats. Although there was no statistical difference among the groups in terms of Fe percentage of breast meat, HS22.5 tended to increase Fe content of thigh meat compared to HS7.5. HS15 and HS22.5 increased redness of breast 8
meat. Although the L* and a* values of breast meat and the L* and b* values of thigh meat decreased by high levels of HS administration, the colour characteristics for all treatments in the current study were within the normal range (Qiao et al., 2002; Ozturk et al., 2010, 2012). Thus the meats and the changes in colour attributes would not be considered excessively pale or dark and favourable, respectively. Therefore, our results confirmed suggestions by Ozturk
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et al. (2012).
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water may be due to metal chelating effects of humic acids (Rath et al., 2006; Šamudovská
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and Demeterová, 2010) that are affected by a large number of carboxylic acid side chains. Our results with respect to other mineral concentrations in meats are in general agreement
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with a previous study (Avci et al., 2007) in which humic acid was used in broiler chickens diets. Comparing results of studies by research worldwide, performance differences due to humate supplementation might result from the compositional differences among the commercially available humate products (Kocabagli et al. 2002; Ozturk et al., 2010, 2012;
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Šamudovská and Demeterová, 2010).
Our results with respect to the weight gain, feed intake and feed efficiency are in agreement with a previous study (Eren et al., 2000) using humic acid in broiler diets.
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However, Kocabagli et al. (2002) found that adverse effects disappear promptly after two weeks. These authors agreed that feeding humic acid to broilers had a growth-promoting effect only during the later stage of growth (22 to 42 d). Therefore, our results support these
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The changes of Zn, P and Fe concentrations in meats by HS administration in drinking
results due to the recovering tendency observed in body weight gain after two weeks of rearing. Although the caecal microbial count were not affected by HS in drinking water in the present study, Shermer et al. (1998) and Ceylan et al. (2003) indicated that the humic acid is an alternative to antibiotic growth promoters in broiler diets by altering the microflora in the gastrointestinal system, especially in the caecum. Therefore, the previous findings related to humic acid (Kocabagli et al., 2002; Ceylan et al., 2003; Esenbuga et al., 2008; Windisch et 9
al., 2008; Aksu and Bozkurt, 2009; Šamudovská and Demeterová, 2010) are somewhat contradictory and not helpful in interpreting our data regarding growth, feed intake and feed efficiency. Eren et al. (2000) also indicated insignificant changes in feed conversion efficiency due to continuous addition of humic acid. The fact that HS treated water did not affect the daily weight gain and feed efficiency
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might result from doses of HS administered or lacking of stress factor in the present study.
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the present study had a fairly high body weight gain compared to birds received the HS
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treated water. Responses to alternatives to antibiotic growth promoters may be greater in a more challenging environment (Ocak et al., 2009; Ozturk et al., 2010, 2012). According to
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these findings, it can be said that feed additives such as humic acids or humates (Midilli et al., 2008) are not effective if there are no stress factors. The result with respect to mortality showed that broilers in the present study were kept under clean and comfortable environmental conditions. It was reported that humic acids stabilise the intestinal flora and
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thus ensure an improved utilisation of nutrients in animal feed (Islam et al., 2005). Aksu and Bozkurt (2009) have reported that 150 g/kg humic acid inclusion into broiler feed decreased the E. coli count. On the contrary, there was no change among the groups with regard to
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intestinal microflora in this study; however, E. coli count in ileum samples tended to decrease. The result of the present study indicate that 7.5, 15 and 22.5 g/kg HS per bird provided
through drinking water appears to have no measurable impact on growth performance, feed
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Indeed, broilers in our previous studies (Ozturk et al., 2010, 2012) and in the control group of
efficiency and caecal microflora, but have a measurable impact on lightness, redness and yellowness of breast and thigh meat colours in broilers, respectively. The data presented on the effects of HS in chickens for fattening would not suffice to encourage producers or authorities for use of HS as feed additive. In conclusion, it has been shown that inclusion of HS into broiler drinking water has no positive effect on broiler performance parameters, gut microflora and mortality but, inclusion of 15 and 22.5 g/kg HS decreased lightness of breast 10
and thigh meat and increased redness of breast meat and decreased yellowness of thigh meat. Further research should focus on the identification of optimal concentrations of feed additive and feeding strategy. ACKNOWLEDGEMENT This study was supported by Research Fund of Agriculture Faculty, Ondokuz Mayis
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University (Z-445), approved by the local Ethical Committee of Ondokuz Mayis University
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repetition of previous experiments. The authors are grateful for the support of the staff and
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facilities of the Animal Science Department, Agriculture Faculty, Ondokuz Mayis University, and also for mineral analyses to Dr. A. Horuz and for reviewing to Dr. A. V. Garipoglu.
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biomedicine. Journal of Applied Biomedicine, 3: 13–24.
RATH, N. C., HUFF, E. W. & HUFF, G. R. (2006) Effects of humic acid on broiler chickens. Poultry Science, 85: 410-414.
QIAO, M, FLETCHER, D. L., NORTHCUTT, J. K. & SMITH D. P. (2002). The relationship between raw broiler breast meat color and composition. Poultry Science, 81: 422–427.
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ŠAMUDOVSKA., A. & DEMETEROVÁ, M. (2010) Effect of diet supplemented with natural humic compounds and sodium humate on performance and selected metabolic variables in broiler chickens. Acta Veterinaria Brno, 79: 385–393. SHERMER. C.L., MACIOROWSKI. K. G., BAILEY. C. A., BYERS, F. M. & RICKE, S. C. (1998) Caecal metabolites and microbial populations in chickens consuming diets containing
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a mined humate compound. Journal of the Science of Food and Agriculture, 77: 479–
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WINDISCH, W. M., SCHEDLE. K., PLITZNER, C. & KROISMAYR, A. (2008) Use of phytogenic
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products as feed additives for swine and poultry. Journal of Animal Science, 86: 140– 148.
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YANG, H. L., CHIU, H. C. & LU, F. (1996) Effects of humic acid on the viability and coagulant properties of human umbilical vein endothelial cells. American Journal of Hematology, 51: 200–206.
YORUK, M. A., GUL. M., HAYIRLI, A. & MACIT. M. (2004) The effects of supplementation of
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humate and probiotic on egg production and quality parameters during the late laying
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period in hens. Poultry Science, 83: 84–88.
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486.
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Table 1. Ingredients and nutrient composition of diets Finisher
(22 to 35 d)
(36 to 42 d)
Yellow maize
408.6
330.0
416.0
Soybean meal
290.3
276.2
250.0
Sunflower meal
77.0
0.0
Cracked wheat
100.0
65.0
Wheat bran
0.0
200.0
Meat and bone meal
64.0
64.0
Vegetable oil
52.0
56.2
50.0
Sodium chloride
2.3
2.3
2.4
Vitamin and mineral premix1
3.5
3.5
2.5
1.2
1.2
1.2
1.1
1.6
1.6
13.0
13.4
13.4
890.0
887.0
889.0
230.0
210.0
190.0
10.1
10.0
8.0
5.0
4.8
4.4
DL-Methionine
0.0
125.0 100.0 51.3
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L-Lysine
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(1 to 21 d)
ME, MJ/kg Dry matter Ca
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Crude Protein Available P
Supplied per kg diet: trans-retinyl acetate 12000 IU, cholecalciferol 2400 IU, DL-α-
ce
1
d
Calculated nutrition composition (g/kg)
tocopheryl acetate 40 mg, menadione 4 mg, thiamine 3 mg, riboflavin 6 mg, nicotinic acid 25 mg, folic acid 1 mg, calcium-D-pantothenat 10 mg, pyridoxine 5 mg, cyanocobalamin 0.03
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Ingredients (g/kg)
Grower
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Starter
mg, D-biotin 0.05 mg; manganese 80 mg, zinc 60 mg, iron 60 mg, copper 5 mg, cobalt 0.2 mg; iodine 1 mg, selenium 0.15 mg, choline chloride 200 mg.
15
Table 2. Initial body weight, daily weight gain, daily feed intake and feed efficiency of broilers receiving humic substances in drinking water HS7.5
HS15
HS22.5
SEM
P-value
Initial body weight, g per bird
50.0
49.8
49.9
50.0
0.07
NS
Daily weight gain, g per bird
54.1
54.1
54.2
54.4
0.67
NS
Daily feed intake, g per bird
95.3
96.4
95.2
94.9
0.67
NS
0.01
NS
1.78
1.76
Data represent the mean value of 4 replicate pens of 30 birds.
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SEM, standard error of mean.
1.74
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1.76
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NS, P > 0.05.
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Feed efficiency, g feed:g gain
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HS0
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Table 3. Carcass weight, dressing percentage and cut-up parts of broilers receiving humic substances in drinking water (mean, n=16) HS0
HS7.5
HS15
HS22.5
SEM
P-value
Carcass weight (g)
1609
1611
1634
1642
20.3
NS
Dressing percentage (%)
70.84
71.79
71.90
70.88
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NS
8.71
8.72
8.75
8.80
0.243
NS
Empty gizzard
1.97
2.08
2.16
2.27
0.056
NS
Heart
0.64
0.65
0.66
0.67
0.014
NS
Liver
2.58
2.72
2.75
2.82
0.050
NS
Abdominal fat
2.72
2.81
2.99
3.16
0.157
NS
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NS, P > 0.05.
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SEM, standard error of mean.
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Whole gut
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Relative weight of (g/100 g body weight)
0.488
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Table 4. Colour measurements of breast and thigh meats of broilers receiving humic substances in drinking water (mean, n=16) HS0
HS7.5
HS15
HS22.5
SEM
P-value
L*, lightness
54.71a
53.88ab
53.08b
52.88b
0.513
*
a*, redness
3.47
3.61
3.67
3.81
0.075
NS
b*, yellowness
2.57a
1.84b
1.75b
0.36c
0.100
*
L*, lightness
47.94a
49.04a
46.18b
46.04b
0.278
*
a*, redness
1.55a
2.02b
2.06b
2.08b
0.097
*
0.249
NS
a,b,c
2.72
2.28
2.17
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1.94
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b*, yellowness
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Thigh meat
Mean values within the same row sharing a common superscript letter are not statistically
different at P < 0.05.
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*P < 0.05; NS, P > 0.05.
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SEM, standard error of mean.
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Breast meat
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Table 5. Mineral composition (ppm on fresh matter) of breast and thigh meats from broilers receiving humic substances in drinking water (mean, n=16) HS0
HS7.5
HS15
HS22.5
SEM
P-value
7.4
16.9
7.0
5.9
0.20
NS
Mg
42.3
49.5
40.8
39.8
0.27
NS
K
258.6
279.5
243.1
247.4
1.16
NS
Na
8.7
10.0
11.8
10.0
P
94.2
101.5
96.1
90.2
Fe
0.7
0.7
1.2
Cu
0.1
0.1
Zn
0.6a
0.8b
Ca
4.6
4.6
Mg
40.8
K
280.1
Na
8.8
P
Fe
NS
0.23
NS
0.9
0.01
NS
0.1
0.2
0.02
NS
0.7ab
0.7ab
0.03
*
6.2
6.8
0.49
NS
40.8
1.50
NS
281.6
288.0
258.7
8.39
NS
9.3
9.0
9.8
0.45
NS
98.9ab
101.7b
90.4a
97.3ab
1.67
*
1.3ab
0.7a
1.0ab
1.9b
0.19
*
40.5
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ce a,b,c
44.0
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Thigh meat
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0.06
d
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Ca
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Breast meat
Cu
0.3
0.2
0.2
0.2
0.04
NS
Zn
0.7
0.6
0.6
0.7
0.04
NS
Mean values within the same row sharing a common superscript letter are not statistically
different at P < 0.05. SEM, standard error of mean. *P < 0.05; NS, P > 0.05.
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Table 6. Bacterial counts (log10 cfu/g) from the caecal content of broilers receiving humic
HS7.5
HS15
HS22.5
SEM
P-value
Aerobic mesophiles
8.65
8.55
8.74
8.30
0.090
NS
Lactococci on M17
7.53
7.53
7.62
7.28
0.120
NS
Lactobacilli on Rogosa
7.72
8.33
7.40
7.94
0.170
NS
Coliforms
7.51
6.91
6.91
7.15
0.110
NS
E. coli
6.74
6.66
6.58
6.38
0.097
NS
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SEM, standard error of mean.
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HS0
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NS, P > 0.05.
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substances in drinking water (mean, n=16)
20
British Poultry Science Publication details, including instructions for authors and subscription information: http://www.tandfonline.com/loi/cbps20
Performance, meat quality, meat mineral contents and caecal microbial population responses to humic substances administered in drinking water in broilers a
b
a
a
c
E. Ozturk , I. Coskun , N. Ocak , G. Erener , M. Dervisoglu & S. Turhan
c
a
Department of Animal Science, Faculty of Agriculture, Ondokuz Mayis University, Kurupelit, 55139 Samsun b
Department of Animal Science, Faculty of Agriculture, Ahi Evran University, Asikpasa, 40000 Kirsehir c
Department of Food Engineering, Faculty of Engineering, Ondokuz Mayis University, Kurupelit, 55139 Samsun, Turkey Accepted author version posted online: 03 Sep 2014.
To cite this article: E. Ozturk, I. Coskun, N. Ocak, G. Erener, M. Dervisoglu & S. Turhan (2014): Performance, meat quality, meat mineral contents and caecal microbial population responses to humic substances administered in drinking water in broilers, British Poultry Science, DOI: 10.1080/00071668.2014.960807 To link to this article: http://dx.doi.org/10.1080/00071668.2014.960807
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Publisher: Taylor & Francis & British Poultry Science Ltd Journal: British Poultry Science DOI: 10.1080/00071668.2014.960807
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CBPS-2014-099 Ed. Kjaer, July 2014; MacLeod, August 2014
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responses to humic substances administered in drinking water in broilers
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E. OZTURK, I. COSKUN1, N. OCAK, G. ERENER, M. DERVISOGLU2 AND S. TURHAN2
Department of Animal Science, Faculty of Agriculture, Ondokuz Mayis University, Kurupelit, 55139 Samsun, 1Department of Animal Science, Faculty of Agriculture, Ahi Evran University, Asikpasa, 40000 Kirsehir and 2Department of Food Engineering, Faculty of Engineering,
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Ondokuz Mayis University, Kurupelit, 55139 Samsun, Turkey
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Running title: Humıc substances as growth promoters
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Performance, meat quality, meat mineral contents and caecal microbial population
Correspondence to: Ergin Ozturk, Ondokuz Mayis Universitesi, Ziraat Fakultesi, Zootekni Bolumu Kurupelit, 55139 Samsun, Turkey. E-mail: [email protected] Tel: +90–362–31231919 x (1144). Fax: +90–362- 4576034.
Accepted for publication 10 thJune 2014 1
Abstract 1. This study was conducted to examine the effect of different levels of humic substances (HS) administered in drinking water on caecal microflora and mineral composition and colour characteristics of breast and thigh meats as well as the growth performance, carcass and gastrointestinal tract (GIT) traits of broiler chicks. 2. A total of 480 3-d-old broilers chickens were randomly allocated to 4 treatments with 4
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cages per treatment and 30 birds (15 males and 15 females) chicks per cage. All birds were
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additions whereas birds in the other treatment groups received a drinking water with 7.5
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(HS7.5), 15.0 (HS15.0) and 22.5 (HS22.5) g/kg HS. Mush feed were provided on an ad libitum basis. Body weight and feed intake of broilers were determined at d 0, 21, and 42, and
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feed conversion ratio was calculated. On d 42, 4 broilers (2 males and 2 females) from each cage were slaughtered and the breast and thigh meats were collected for mineral composition and quality measurements.
3. Performance, carcass and GIT traits and caecal microbial population of broiler chicks at d
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42 were not affected by the dietary treatments. The lightness (L*) of breast and thigh meat decreased in broilers supplemented with 15 g/kg and 22.5 g/kg HS in drinking water. While the redness (a*) of breast meat increased, yellowness of thigh meat decreased in broilers
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supplemented with 15 g/kg and 22.5 g/kg HS in drinking water (P < 0.05). 4. In conclusion, the 15 g/kg and 22.5 g/kg HS administration in drinking water can be applied for broiler chicks to maintain growth performance and improve meat quality without
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fed on commercial basal diet. The control birds (HS0) received drinking water with no
changing caecal microflora. INTRODUCTION
The optimum growth and economical feed conversion as well as prevention and control of diseases are dependent on the feed additives (Ozturk et al., 2012). There is a large variety of feed additives including organic acids such as acetic, propionic, butyric, formic, citric, fumaric, lactic, malic acid and humic acids or commercial acid blends (Islam et al., 2005; 2
2008; Esenbuga et al., 2008; Ocak et al., 2009; Ozturk et al., 2010, 2012), that can be used to replace antibiotic growth promoters. Humic substances (HS) are major components of the natural organic matter in soil and water as well as in geological organic deposits such as lake sediments, peats, brown coals and shales (Islam et al., 2005). The HS, humic, fulmic and ulvic acids are not antibiotics but, if used correctly along with nutritional, managerial and bio-
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security measures, they can be a powerful tool in maintaining the health of the gastrointestinal
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al., 2003; Windisch et al., 2008). Most of the data on humic, fulmic, ulvic acids and humin
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refer to average properties and structure of a large ensemble of components of diverse structure and molecular weight (Islam et al., 2005; Ozturk et al., 2010, 2012). The properties
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of HS are well documented (Islam et al., 2005; Peña-Méndez et al., 2005; Ji et al., 2006). Studies investigating the effects of the HS and/or humic acids administration in the diet or drinking water on live weight, feed consumption and characteristics of carcass and GIT in broiler chickens (Rath et al., 2006; Ozturk et al., 2010, 2012; Šamudovská and
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Demeterová, 2010) indicated that HS improved protein digestion and trace element utilisation (Huang et al., 1994; Yang et al.,1996,), and it has a positive influence on growth rate (Shermer et al., 1998; Eren et al., 2000; Kocabagli et al., 2002; Ceylan et al., 2003). We
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found that the HS supplementation at levels of 300 g/kg and 450 g/kg in drinking water appears to have a measurable impact on live performance by improving feed efficiency and lightness of breast and thigh meat in broilers, respectively (Ozturk et al., 2010). Also we
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tract (GIT) of poultry, thus improving their performances (Kocabagli et al., 2002; Ceylan et
found that feeding with a diet containing HS caused a measurable variation in the meat quality and blood cholesterol as well as the performance, carcass, and GIT traits of broilers. The antimicrobial effects of humic substances, including humic acid, have been demonstrated, but the reports on their influence on growth performance of poultry are variable, therefore, it needs more investigation (Ozturk et al., 2010, 2012). On the other hand, little is known on whether humic acid shows an antimicrobial effect against opportunistic pathogens existing in 3
gastrointestinal tract (Islam et al., 2008). Thus, the aim of this study was to evaluate the effects of different doses of HS supplementation provided through drinking water on growth performance, characteristics of carcass and gut, gut microflora and colour characteristics of breast and thigh meat in broilers. MATERIALS AND METHODS
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For the trial, 480 3-d-old broiler chicks (ROSS 308), were allocated into 4 groups (HS0,
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replicates of 30 chicks (15 females and 15 males). All birds were fed ad libitum the same
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antibiotic-free commercial diet for the starter (from d 1 to d 21), grower (from d 22 to d 35) and finisher (from d 36 to d 42) periods (Table 1). All animals in experimental treatments
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were housed in floor pens with wood shavings and fed on the same basic diets. The control birds (HS0) received drinking water with no additions. Birds in the other treatment groups received a drinking water with 7.5 (HS7.5), 15.0 (HS15.0) and 22.5 (HS22.5) g/kg HS per kg of body weight. The liquid HS, measured for each of treatments was added into a sufficient
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amount of drinking water based on estimated water consumption recommended by the producer company. Therefore, drinking water was prepared daily for each of treatments and also to ensure consumption of HS treated water, the treated water up to the half of daily water
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requirement were given by plastic poultry drinker. After all of the HS treated water was consumed, birds were watered ad libitum by automatic drinkers. Thus, daily water intake was not measured. The HS used in present study was reported to include 4.9% dry matter, 61.2%
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HS7.5, HS15 and HS22.5) of 120 mixed-sex birds. Each treatment was divided into 4
humic acid, 5.1% fulvic acid, 7.53% crude protein, 0.48% crude fibre, 2.35% ether extract, 2.49 % Ca 0.24%Mg, 0.15% K, 1.09% N, 1.49% S, 0.07% P, 0.28% NO3-, 1.89% Fe, 0.05%
Zn, 0.02% Cu, 0.01% Ni, 0.02% Cr, respectively (Ozturk et al., 2012).
Table 1 near here
During the trial, continuous lighting was provided throughout the experiment. Ambient temperature was gradually decreased from 33 °C on d 7 to 21 °C on d 21 and was kept constant. All the cages were checked for mortality twice a d and mortality was recorded as it 4
occurred and was used to adjust the total number of birds to determine the total feed intake per bird and FCR. Live weight and feed intake were measured at 1, 21, 35 and 42 d of age. The birds were weighed and fed as mixed sex in each group. Therefore the chick weight, the daily weight gain and the feed efficiency was not determined per sex. At 42 d of age, birds were starved for 6 h before slaughtering and 4 birds (2 females and 2 males) per replicate or
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16 birds per treatment were slaughtered (Ozturk et al., 2010, 2012). Plucked and eviscerated
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ready-to cook carcasses that were refrigerated for 6 h at 4 °C. Yields from chilled carcasses,
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breast and thighs were evaluated. Breast (Pectoralis major) and thigh (Iliotibialis) meat samples were vacuum-packaged and kept frozen (-20 °C) until chemical analyses were
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performed.
The CIE colour values of meats (lightness (L*), redness (a*), and yellowness (b*)) were measured at 8 h post-mortem using a Minolta CR 300 Chroma Meter (Minolta Camera Co., Osaka, Japan). Four replicate measures were performed on breast and thigh meats,
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respectively, representing the whole surface of the muscles and mean colour values were calculated for each sample. The colorimeter was calibrated throughout the study using a white and pink ceramic tile. A white tile (L* = 92.30, a* = 0.32, and b* = 0.33) was used as
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standard. Lightness may range from 100 (white) to 0 (black). While positive a* and b* values are a measure of redness and yellowness, respectively, negative a* and b* values indicate greenness and blueness. Mineral composition of breast and thigh meat was determined with
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carcasses were weighed after removal of the head, neck, feet and abdominal fat to obtain
atomic absorption spectrophotometer, except P that was analysed with an atomic absorption spectrophotometer (Horuz and Korkmaz, 2006). Pre-weighed ileum samples (1 g) for microbiological analyses were transferred into dilution bottles. Anaerobic diluents were added to achieve a 1 to 10 (w/v) dilution. The samples were mixed with a vortex until completely suspended and dispensed using standard methods into a 1 to 10 (v/v) dilution series of tubes containing anaerobic peptone buffer. 5
Appropriate dilutions were inoculated onto the plates. The following media and incubation conditions were used to enumerate microbial counts of samples: Rogosa agar for lactobacilli at 30oC for 5 d, Plate Count agar for aerobic mesophilic bacteria at 30oC for 48 h, Violet-Red Bile agar for coliform bacteria at 35oC for 24 h, M17 agar for lactococci at 30oC for 72 h and Chromocult TBX agar for Escherichia coli (E. coli) at 44oC for 24 h.
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For performance data, pen means served as the experimental unit for statistical
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composition, blood parameters and caecal microbial population, slaughtered individual birds
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were considered as the experimental unit. All percentage data were transformed by taking arcsine square roots prior to analysis. In order to evaluate statistically the measured data, one-
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way analysis of variance (ANOVA) was performed in a completely randomised design: ˆYij = μ + αi + eij (ˆYij: observation values (body weight gain, feed consumption, feed to gain, carcass traits, colour measurements, blood parameters, etc.), μ: the overall mean, αi: the effect of the ith treatment (i: 1, . . ., 4; HS0, HS7.5, HS15.0 and HS22.5) and eij = residual error).
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Tukey's test was used to determine the effect of treatments and differences which were considered to be significant at P < 0.05. RESULTS
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No significant differences in mortality among the treatment groups (0.83%, 1.67%, 0.83% and 0.83% for the HS0, HS7.5, HS15 and HS22.5, respectively) were observed. Daily weight gain, daily feed intake and feed efficiency of broilers receiving the HS supplemented drinking
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analysis. For data of relative weights and length of gut, meat quality traits, chemical
water are presented in Table 2. The daily weight gain, daily feed intake and feed efficiency
were not affected by the treatments (P > 0.05). Therefore, HS administered in drinking water did not have any harmful effects on performance, and had no growth-promoting effect compared to control on broilers.
Table 2 near here
Means for carcass weight, dressing percentage, the relative weight and length of gut and the relative weight of edible inner organs (such as gizzard, heart, liver) and abdominal fat 6
pad at 42 d of age are shown in Table 3. There were no differences among the experimental groups compared to the control group in terms of the carcass weight, dressing percentage, the relative weight and length of gut and the relative weight of edible inner organs and abdominal fat pad (P > 0.05). The L* and a* values of breast and L* and b* values of thigh meat were affected by
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HS supplementation (Table 4), the L* values of breast meat were higher at 0HS than that of
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lower than those from other treatment birds (P < 0.05). The L* values of thigh meat was
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higher in control and 7.2HS birds than those in other treatments (P < 0.05). The thigh meat from all of the HS treatment groups had a higher a* value compared to the HS0 (P < 0.05).
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Mineral composition of breast and thigh meats of broilers receiving the HS supplemented drinking water is presented in Table 5. Percentages of Ca, Mg, K, Na, P, Fe and Cu of breast meat were not affected by the dietary treatments, but content of Zn increased by HS7.5 in respect to 0HS. Percentages of Ca, Mg, K, Na, Cu and Zn of thigh meat were not
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affected by the dietary treatments, but percentage of P was higher in HS7.5 compared to HS15 whereas Fe level was higher in HS22.5 compared to HS7.5.
Tables 4 and 5 near here
Bacterial counts (log10 cfu/g) from the caecal of broilers receiving HS-supplemented
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drinking water are presented in Table 6. Aerobic mesophiles, lactococci, lactobacilli, coliforms and E. coli counts in caecum were not affected by HS in drinking water (Table 6).
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15HS and 22.5HS groups (P < 0.05). The b* values of breast meat from 22.5HS birds were
DISCUSSION
Table 6 near here
The results of the present study indicated that the 15 g/kg and 22.5 g/kg HS administration in drinking water can be applied for broiler chicks to maintain growth performance, without changing caecal microflora, and to improve meat quality. In the present study, mortality was low and within the accepted limit for all groups, and the deaths was not associated with any specific treatment. Our result could be considered as similar to our previously observations (Ozturk et al., 2010, 2012). Likewise, Rath et al. (2006) and Kocabagli et al. (2002) found no 7
differences in mortality in their study. It can be said that the potential interactions of HS with commonly occurring pathogens or environmental stress can hardly be evaluated under the controlled conditions. Therefore, it is considered that the cause of death of chickens in control and HS groups was the sudden death syndrome, conforming to the results of studies by Yoruk et al. (2004), Karaoglu et al. (2004) and Islam et al. (2008). The fact that HS treated water did
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not induce deterioration in feed intake and weight gain in our present and previous study
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Indeed, we observed that, in the both experiments, birds consumed voluntary all of the HS
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treated water.
External appearance (colour) of meat and consistency of colour as well as water-
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holding capacity and texture are important meat quality characteristics that can affect consumer preferences (Fletcher, 2002; Qiao et al., 2002). Moreover, there is a relationship among some meat quality parameters such as colour attributes (CIE L*, a* and b*), pH and water-holding capacity (Fletcher, 2002). Colour of meat is not only a quality characteristic,
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but is also an indicator of animal health, related directly to stress and energy metabolism (Nijdam et al., 2005; Kop and Ocak, 2009). Therefore, one of the primary aims of the present study was to investigate the changes in colour characteristics and chemical compositions of
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both breast and thigh meats. Yoruk et al. (2004) have demonstrated that darkening in thigh muscles and an increase in their redness might indicate an increase in haem pigments because the red colour in meat is due mainly to a protein pigment called myoglobin and, to a lesser
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(Ozturk et al., 2010) indicate that HS given in drinking water did not affect water intake.
extent, haemoglobin. Ozturk et al. (2010) have reported that inclusion of 0.5 g/kg HS via water enhanced a* values of broiler breast and thigh meat and Ozturk et al. (2012) have hypothesised that the increase of a* values of breast and thigh meat might result from increased iron content of breast and thigh meats. Although there was no statistical difference among the groups in terms of Fe percentage of breast meat, HS22.5 tended to increase Fe content of thigh meat compared to HS7.5. HS15 and HS22.5 increased redness of breast 8
meat. Although the L* and a* values of breast meat and the L* and b* values of thigh meat decreased by high levels of HS administration, the colour characteristics for all treatments in the current study were within the normal range (Qiao et al., 2002; Ozturk et al., 2010, 2012). Thus the meats and the changes in colour attributes would not be considered excessively pale or dark and favourable, respectively. Therefore, our results confirmed suggestions by Ozturk
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et al. (2012).
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water may be due to metal chelating effects of humic acids (Rath et al., 2006; Šamudovská
us
and Demeterová, 2010) that are affected by a large number of carboxylic acid side chains. Our results with respect to other mineral concentrations in meats are in general agreement
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with a previous study (Avci et al., 2007) in which humic acid was used in broiler chickens diets. Comparing results of studies by research worldwide, performance differences due to humate supplementation might result from the compositional differences among the commercially available humate products (Kocabagli et al. 2002; Ozturk et al., 2010, 2012;
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Šamudovská and Demeterová, 2010).
Our results with respect to the weight gain, feed intake and feed efficiency are in agreement with a previous study (Eren et al., 2000) using humic acid in broiler diets.
ce
However, Kocabagli et al. (2002) found that adverse effects disappear promptly after two weeks. These authors agreed that feeding humic acid to broilers had a growth-promoting effect only during the later stage of growth (22 to 42 d). Therefore, our results support these
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The changes of Zn, P and Fe concentrations in meats by HS administration in drinking
results due to the recovering tendency observed in body weight gain after two weeks of rearing. Although the caecal microbial count were not affected by HS in drinking water in the present study, Shermer et al. (1998) and Ceylan et al. (2003) indicated that the humic acid is an alternative to antibiotic growth promoters in broiler diets by altering the microflora in the gastrointestinal system, especially in the caecum. Therefore, the previous findings related to humic acid (Kocabagli et al., 2002; Ceylan et al., 2003; Esenbuga et al., 2008; Windisch et 9
al., 2008; Aksu and Bozkurt, 2009; Šamudovská and Demeterová, 2010) are somewhat contradictory and not helpful in interpreting our data regarding growth, feed intake and feed efficiency. Eren et al. (2000) also indicated insignificant changes in feed conversion efficiency due to continuous addition of humic acid. The fact that HS treated water did not affect the daily weight gain and feed efficiency
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might result from doses of HS administered or lacking of stress factor in the present study.
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the present study had a fairly high body weight gain compared to birds received the HS
us
treated water. Responses to alternatives to antibiotic growth promoters may be greater in a more challenging environment (Ocak et al., 2009; Ozturk et al., 2010, 2012). According to
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these findings, it can be said that feed additives such as humic acids or humates (Midilli et al., 2008) are not effective if there are no stress factors. The result with respect to mortality showed that broilers in the present study were kept under clean and comfortable environmental conditions. It was reported that humic acids stabilise the intestinal flora and
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d
thus ensure an improved utilisation of nutrients in animal feed (Islam et al., 2005). Aksu and Bozkurt (2009) have reported that 150 g/kg humic acid inclusion into broiler feed decreased the E. coli count. On the contrary, there was no change among the groups with regard to
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intestinal microflora in this study; however, E. coli count in ileum samples tended to decrease. The result of the present study indicate that 7.5, 15 and 22.5 g/kg HS per bird provided
through drinking water appears to have no measurable impact on growth performance, feed
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Indeed, broilers in our previous studies (Ozturk et al., 2010, 2012) and in the control group of
efficiency and caecal microflora, but have a measurable impact on lightness, redness and yellowness of breast and thigh meat colours in broilers, respectively. The data presented on the effects of HS in chickens for fattening would not suffice to encourage producers or authorities for use of HS as feed additive. In conclusion, it has been shown that inclusion of HS into broiler drinking water has no positive effect on broiler performance parameters, gut microflora and mortality but, inclusion of 15 and 22.5 g/kg HS decreased lightness of breast 10
and thigh meat and increased redness of breast meat and decreased yellowness of thigh meat. Further research should focus on the identification of optimal concentrations of feed additive and feeding strategy. ACKNOWLEDGEMENT This study was supported by Research Fund of Agriculture Faculty, Ondokuz Mayis
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University (Z-445), approved by the local Ethical Committee of Ondokuz Mayis University
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repetition of previous experiments. The authors are grateful for the support of the staff and
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facilities of the Animal Science Department, Agriculture Faculty, Ondokuz Mayis University, and also for mineral analyses to Dr. A. Horuz and for reviewing to Dr. A. V. Garipoglu.
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REFERENCES
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AVCI, M., DENEK, N. & KAPLAN, O. (2007) Effects of humic acid at different levels on growth performance, carcass yields and some biochemical parameters of quails. Journal of Animal and Veterinary Advances, 6: 1–4.
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CEYLAN, N., CIFTCI, I. & ILHAN, Z. (2003) The effects of some alternative feed additives for antibiotic growth promoters on the performance and gut microflora of broiler chicks. Turkish Journal of Veterinary and Animal Sciences, 27: 727–733.
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ESENBUGA, N., MACIT, M., KARAOGLU, M., AKSU, M. I. & BILGIN, O. C. (2008) Effects of dietary humate supplementation to broilers on performance, slaughter, carcass and meat color. Journal of the Science of Food and Agriculture, 88: 1201–1207. FLETCHER, D. L. (2002) Poultry meat quality. World’s Poultry Science Journal, 58: 131–146. HORUZ, A. & KORKMAZ, A. (2006) Farklı sürgün dönemlerinde hasat edilen çayın verimi, azot
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JI, F., MCGLONE, J. J. & KIM, S. W. (2006) Effects of dietary humic substances on pig growth performance, carcass characteristics, and ammonia emission. Journal of Animal Science, 84: 2482–2490.
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KARAOGLU, M., MACIT. M., ESENBUGA. N., DURDAG, H., TURGUT, L. & BILGIN, O. C. (2004) Effect of supplemental humate at different levels on the growth performance slaughter and carcass traits of broilers. International Journal of Poultry Science, 3: 406–410.
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MIDILLI, M., ALP, M., KOCABAGLI. N., MUGLALI, O. H., TURAN. N., YILMAZ, H. & CAKIR, S. (2008) Effects of dietary probiotic and prebiotic supplementation on growth performance and serum IgG concentration of broilers. South African Journal of Animal Science, 38: 21–27. NIJDAM, E., DELEZIE. E., LAMBOOIJ. E., NABUURS. M. J. A., DECUYPERE, E., & STEGEMAN, J.
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OZTURK, E, OCAK. N., TURAN, A., ERENER, G., ALTOP, A. & CANKAYA, S. (2012) Performance, carcass, gastrointestinal tract and meat quality traits, and selected blood parameters of broilers fed diets supplemented with humic substances. Journal of the
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ŠAMUDOVSKA., A. & DEMETEROVÁ, M. (2010) Effect of diet supplemented with natural humic compounds and sodium humate on performance and selected metabolic variables in broiler chickens. Acta Veterinaria Brno, 79: 385–393. SHERMER. C.L., MACIOROWSKI. K. G., BAILEY. C. A., BYERS, F. M. & RICKE, S. C. (1998) Caecal metabolites and microbial populations in chickens consuming diets containing
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WINDISCH, W. M., SCHEDLE. K., PLITZNER, C. & KROISMAYR, A. (2008) Use of phytogenic
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YANG, H. L., CHIU, H. C. & LU, F. (1996) Effects of humic acid on the viability and coagulant properties of human umbilical vein endothelial cells. American Journal of Hematology, 51: 200–206.
YORUK, M. A., GUL. M., HAYIRLI, A. & MACIT. M. (2004) The effects of supplementation of
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486.
14
Table 1. Ingredients and nutrient composition of diets Finisher
(22 to 35 d)
(36 to 42 d)
Yellow maize
408.6
330.0
416.0
Soybean meal
290.3
276.2
250.0
Sunflower meal
77.0
0.0
Cracked wheat
100.0
65.0
Wheat bran
0.0
200.0
Meat and bone meal
64.0
64.0
Vegetable oil
52.0
56.2
50.0
Sodium chloride
2.3
2.3
2.4
Vitamin and mineral premix1
3.5
3.5
2.5
1.2
1.2
1.2
1.1
1.6
1.6
13.0
13.4
13.4
890.0
887.0
889.0
230.0
210.0
190.0
10.1
10.0
8.0
5.0
4.8
4.4
DL-Methionine
0.0
125.0 100.0 51.3
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L-Lysine
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(1 to 21 d)
ME, MJ/kg Dry matter Ca
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Crude Protein Available P
Supplied per kg diet: trans-retinyl acetate 12000 IU, cholecalciferol 2400 IU, DL-α-
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1
d
Calculated nutrition composition (g/kg)
tocopheryl acetate 40 mg, menadione 4 mg, thiamine 3 mg, riboflavin 6 mg, nicotinic acid 25 mg, folic acid 1 mg, calcium-D-pantothenat 10 mg, pyridoxine 5 mg, cyanocobalamin 0.03
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Ingredients (g/kg)
Grower
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Starter
mg, D-biotin 0.05 mg; manganese 80 mg, zinc 60 mg, iron 60 mg, copper 5 mg, cobalt 0.2 mg; iodine 1 mg, selenium 0.15 mg, choline chloride 200 mg.
15
Table 2. Initial body weight, daily weight gain, daily feed intake and feed efficiency of broilers receiving humic substances in drinking water HS7.5
HS15
HS22.5
SEM
P-value
Initial body weight, g per bird
50.0
49.8
49.9
50.0
0.07
NS
Daily weight gain, g per bird
54.1
54.1
54.2
54.4
0.67
NS
Daily feed intake, g per bird
95.3
96.4
95.2
94.9
0.67
NS
0.01
NS
1.78
1.76
Data represent the mean value of 4 replicate pens of 30 birds.
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SEM, standard error of mean.
1.74
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1.76
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NS, P > 0.05.
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Feed efficiency, g feed:g gain
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HS0
16
Table 3. Carcass weight, dressing percentage and cut-up parts of broilers receiving humic substances in drinking water (mean, n=16) HS0
HS7.5
HS15
HS22.5
SEM
P-value
Carcass weight (g)
1609
1611
1634
1642
20.3
NS
Dressing percentage (%)
70.84
71.79
71.90
70.88
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NS
8.71
8.72
8.75
8.80
0.243
NS
Empty gizzard
1.97
2.08
2.16
2.27
0.056
NS
Heart
0.64
0.65
0.66
0.67
0.014
NS
Liver
2.58
2.72
2.75
2.82
0.050
NS
Abdominal fat
2.72
2.81
2.99
3.16
0.157
NS
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NS, P > 0.05.
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SEM, standard error of mean.
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Whole gut
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Relative weight of (g/100 g body weight)
0.488
17
Table 4. Colour measurements of breast and thigh meats of broilers receiving humic substances in drinking water (mean, n=16) HS0
HS7.5
HS15
HS22.5
SEM
P-value
L*, lightness
54.71a
53.88ab
53.08b
52.88b
0.513
*
a*, redness
3.47
3.61
3.67
3.81
0.075
NS
b*, yellowness
2.57a
1.84b
1.75b
0.36c
0.100
*
L*, lightness
47.94a
49.04a
46.18b
46.04b
0.278
*
a*, redness
1.55a
2.02b
2.06b
2.08b
0.097
*
0.249
NS
a,b,c
2.72
2.28
2.17
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1.94
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b*, yellowness
us
Thigh meat
Mean values within the same row sharing a common superscript letter are not statistically
different at P < 0.05.
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*P < 0.05; NS, P > 0.05.
d
SEM, standard error of mean.
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Breast meat
18
Table 5. Mineral composition (ppm on fresh matter) of breast and thigh meats from broilers receiving humic substances in drinking water (mean, n=16) HS0
HS7.5
HS15
HS22.5
SEM
P-value
7.4
16.9
7.0
5.9
0.20
NS
Mg
42.3
49.5
40.8
39.8
0.27
NS
K
258.6
279.5
243.1
247.4
1.16
NS
Na
8.7
10.0
11.8
10.0
P
94.2
101.5
96.1
90.2
Fe
0.7
0.7
1.2
Cu
0.1
0.1
Zn
0.6a
0.8b
Ca
4.6
4.6
Mg
40.8
K
280.1
Na
8.8
P
Fe
NS
0.23
NS
0.9
0.01
NS
0.1
0.2
0.02
NS
0.7ab
0.7ab
0.03
*
6.2
6.8
0.49
NS
40.8
1.50
NS
281.6
288.0
258.7
8.39
NS
9.3
9.0
9.8
0.45
NS
98.9ab
101.7b
90.4a
97.3ab
1.67
*
1.3ab
0.7a
1.0ab
1.9b
0.19
*
40.5
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ce a,b,c
44.0
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Thigh meat
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0.06
d
cr
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Ca
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Breast meat
Cu
0.3
0.2
0.2
0.2
0.04
NS
Zn
0.7
0.6
0.6
0.7
0.04
NS
Mean values within the same row sharing a common superscript letter are not statistically
different at P < 0.05. SEM, standard error of mean. *P < 0.05; NS, P > 0.05.
19
Table 6. Bacterial counts (log10 cfu/g) from the caecal content of broilers receiving humic
HS7.5
HS15
HS22.5
SEM
P-value
Aerobic mesophiles
8.65
8.55
8.74
8.30
0.090
NS
Lactococci on M17
7.53
7.53
7.62
7.28
0.120
NS
Lactobacilli on Rogosa
7.72
8.33
7.40
7.94
0.170
NS
Coliforms
7.51
6.91
6.91
7.15
0.110
NS
E. coli
6.74
6.66
6.58
6.38
0.097
NS
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SEM, standard error of mean.
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HS0
ce
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NS, P > 0.05.
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substances in drinking water (mean, n=16)
20
